I. Field of the Invention
The present invention relates generally to filtering devices and, more particularly, to a filtering device with air bleed means.
II. Description of the Prior Art
There are many types of previously known fluid filtering devices, for example, fluid filtering devices used in hydraulic fluid systems. These fluid filtering devices typically include a housing which defines an interior chamber. An inlet port and an outlet port are provided in the housing and a filter element is disposed within the housing between the inlet port and outlet port. Thus, fluid flowing from the inlet port to the outlet port passes through the filter element to remove contaminants from the fluid. In many types of filtering devices, the filter element is removable from the housing for cleaning and/or replacement with a clean filter element.
It is often desirable to eliminate the accumulation of air in pockets within the fluid system. For example, in a hydraulic system, a large air pocket can cause significant pump cavitation, and result in erosive pump damage and instability of operation of the hydraulic system.
A number of the previously known filtering devices have thus included some means to continuously bleed the air from the fluid in the system in order to prevent accumulation of air. The air is thus passed in small relatively harmless quantities to the fluid flow through the system. In the latter case, the small air bubbles within the fluid do not adversely affect the operation of the fluid system whereas a large air pocket would.
These previously known filtering devices with air bleed means, however, provide for only a very limited number of orientations for the device. The previously known filtering devices are thus disadvantageous in that operation in other desirable orientations is either ineffective or renders the air bleed means inoperable.